Friction brake and clutch.



wf' c. MARSH.

FRIGTION BRAKE AND CLUTCH. APPLIoA'HoN FILED P23111', 190s.

947,683. i I 'Patented 1m25, 191,0.

3 SHEETS-SHEET 1.

. Witwe/oom W. C. MARSH.

FRIGTION BRAKE AND CLUTCH.

l APPLIUATION FILED FBB.11, 1908.

Patented Jan.25,1910.

W. G. MARSH.

FRIGTION BRAKE AND CLUTCH.

APPLICATION FILED PEB.11, 1908.

947,683. Eatented'Jan. 25, 1910.

3 SHEETS-SHEET 3.

Wi h1 @Meo PATENT orme WILLIAM C. OF DUNKIRK, NEW YORK.

Fmo'rIoN BRAKE Ann cLU'rcH..-

To allwhorn 'it may concern:

Be 1t knownthat I, WILLIAM C. MARSH,

a citizen of the United States, residing at4 Dunkirk, in the county of Chautauqua, 'State of New York, have invented new and useful Improvements in Friction Brakes and Clutches, of which the following is a specification.

My invention relates to" friction brakes and clutches, and has for its objects, first, to

provide an improved mechanism t'orapplyhereinafter described and claimed, reference being had to the accompanying drawings, in which:l

Figure 1 is a view partly in side elevation, partly in section on the line .li- A, Fig. 2, and partly in section on the line B--B, Fig. 2. Fig. 2 is a sectional view takenon the line C-C, Fig. 3. Fig. 3 is a View partly in elevation and partly in central vertical transverse section. detail elevation of one of the camv rings. Fig. 5 is a view partly in side elevation and partly in section of a modified construction adapted more particularly for use as a clutch for heavy. machinery. Fig. 6. is a partial transverse sectional view illustrating still another modified construction, the emergency brake mechanism alone being -employed.

Similar numerals of reference denote corresponding parts in the several views.

In the said drawings, which illustrate my improved construction used as a brake for automobiles, the reference numeral-'1 denotes a :fixed casing partly inclosing the'rotating member 2 that is keyed to the shaft 3, or to the hub of the wheel, and whose flange 4 f' forms on its inner surface the contact surface for the brake shoes. Mounted on `the shaft 3, or on a sleeve 5 on said shaft,is a

following the contour of said cam surfaces.

it similanbut shorter sleeve 12 is mounted Fig. 4 is an enlarged on sleeve 6,'and is provided with a lever 13 similar to lever 7 and with a cam ring 14 similar -to cam ring 9.

-A number of blocks 15 corresponding in number to the cam surfaces 10 are mounted to slide in the casing 1 between the same and a division plate 16, said blocks being each bifurcated at 17 at its inner end to receive .a roller 18 mounted on a pintle 19 passing through said bifurcated arms 17, eachof said rollers bearing against one of the cam surfaces-10 of ring 14. The ends of bifurcated arms 17 are inturned at- 20 to engage in the grooves 11 in ring 14, as shown. Also lying between casing 1 and division plate 16 is a series of' blocks 21 extended at their outer ends into brake shoes 22, and.v corresponding in number to that of. blocks 15 to which they are adjustably connected by screw bolts 23 having oppositely pitched screw threads, as shown. As shown in Fig. 2, the casing 1- is projected inward at 24, and the plate 16 is similarly projected vat 25 to embrace the headA of the screw bolts 23 when in position tov retain the latter against rotation.

Coperating with the cam ring 9 through rollers 26 andinturned ends 27, 1n the same manner as'do the blocks 15 with cam ring 14, is a corresponding series of-blocks 28, lyingbetween division plate 16 and a se arating plate 29,' each of said blocks having pivoted thereto at 30 the inner end of a brake shoe 31. Said brake shoes are extended for a distance laterally to each side, but

of a circle slightly smaller in diameter than that of the inner braking surface of the flange 4, and are providedwith abutments 32 contacting with similar abutments 33 on extensions of plate 29 acting to position said brake shoes centrally when retracted.

From the above description the operation of my improved construction will be understood as follows: When it is desired to apply a braking action gradually to shaft 3, the lever 13 is pulled against the tension of its sprngcorresponding to spring 8 (notshown) which will correspondingly rotate its sleeve 12 and cam ring- 14, and through the engagement of cam faces 10 thereon with the rollers 18 of blocks 15 will gradually project outward said blocks and their brake shoe blocks into braking contact with the flange 4. Upon releasing the lever 13 the same will be retracted by its spring, thus returning Specification of Letters Patent. Patented Jan, 25, 1910` Application inea February i1, 190s.l serial No. ai5,42e.

- tional normal inactive positions.

the sleeve 12 and cam ring 14 to their normal positions, the latter through the engagement of the .inturned ends' 20 of blocks l5 with the cam `grooves 11 positively revthrough sleeve 6 and cam ring 9, the result being that as the braking surfaces of said brake shoes are formed on the arc of a circle of greater diameter than that of one stru'ck from the pivotal points of said brake shoes, they will, when brought intocontact with the flange 4, instantly -jam or wedge thereagainst, thus providing a rapid and complete braking action. Upon releasing the lever 7 its spring in retracting thesame, and through it the sleeve 6 and cam ring 9, will positively retract said brake'shoes, thus bringing the abutments 32 and 33 into contact, which, in conjunction with springs 31', will force said brake shoes to their central position and will maintain them in said position.

In considering the operation of the brake shoes 31, it will be observed that said shoes and their blocks 28 move radially with respect to shaft 3, and that the action of cam .ring 9 thereon is also radial, so that the only force necessary to apply said brake shoesis that suficient to overcome their inertia,

l.while the inward thrust caused by said brake shoes tilting into locking engagement with `flange-4 will be exerted against the cam surfaces 10 of cam ring-9 at an angle of substantially 45 de rees to their line of movement, which wil exert substantially no rotatin strain on said cam ring 9, and will there ore require substantially no addiower to resist the same. v

Whi e I have described and illustrated my improved construction in Figs. 1 to 4 as ap` plied to a brake, it will be understood that I contemplate usin the same as a clutch,

which may be gra ually applied until locked *l through brake shoes 22, and then maintained locked'against abnormal strains through the Wedging action of brake shoes 31 as shown for instance in Fig. 5.

In F ig.' 5 I have shown a somewhat mdied construction, wherein I employ, instead of the rotating rings 9 and 14, the cams 34 and 35 carried respectively by sleeves 34 and 35', and movable longitudinally with respect to the shaft 36 to force the brake or clutch shoes into and out of action.' In this 'construction the cam sleeve 35', which opshoes in a manner similar to the operationr of cam ring 14. The driven member of thi` clutch being put in motion by said shoes, the cam sleeve 34 may then be moved to the right, through a shifting lever engaged with groove 37 therein, which through cam surfaces 38 and blocks (not shown) similar to blocks 28 will put into operation shoes similar to shoes 31, whereby the driven member of the clutch will be locked to the driving member. It will be understood that by rcason of the fact that the cams 34 and 35 are arranged in stag 'ered relation with respect t0 each other, wit the cams resting on the sleeve 34 carrying cams 34, thev sleeve 35 and its cams 35 are free to be moved to the right without disturbing cams 34. This construction is peculiarly applicable to clutches for comparatively heavy machinery.

In F ig. 6 I have illustrated still another modification of m novel construction wherein the emergency rake or clutch shoes alone are used.' In this construction the shoe 41 is pivoted vat 42 to a lever43 pivoted at its other end at 44 in the casing, and operated by cam ring 45 through connecting block 46 in the manner similar to the operation of cam ring 9 and block 28. By this construc- 'tion, the brake shoe 41, when forced against the surface 47, will operate when said surface is moving in one direction only, and will freely yield on its pivot 42 when said surface 47 is moving in the opposite direction. This construction is peculiarly adapted for use on automobiles as a safety brake in ascending hills, as the same may be so applie as to permit free movement ahead, but acting an instant and automatic check against movement backward. It will be understood that said construction is intended solely as a supplemental hill brake, and may be employed either in addition to the brake mechanism shown in Figs. 1 to 4, or with any other form of brake mechanism.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: y

1. A friction brake, embodying a member having a braking surface, a brake shoe, means for applying the same to the braking surface so as to gradually' increase its lbraking action thereon, a second brake shoe, a movable block to which said second brake shoe is pivoted, said second brake shoe being adapted when applied to automatically lock of itself against the braking surface, and means for applying said second brake shoe.

2. A friction brake, embodying a member having a braking surface, a brake shoe, means for applying the same to the braking surface so as to gradually increase its 'braking action thereon, a second brake shoe, a radially movable block to which said secondl brake shoe is pivoted, said second brakel shoe being adapted when applied to automat- ICC ica

adapted when applied to automatically lock of itself against the braking surface, and

means for applying said second brake shoe,

bot-h of said ap lying means o erating to move said braife shoes positlvely both toward and from the braking position.

4. A friction brake, embodying a brake shoe, a block connected to said brake shoe, a

roller carriedl by said block, a movable part having a cam surface against which said roller contacts and having cam grooves, and lugs on said block engaging said cam grooves to retract said block and brake shoe.

5. A friction brake, embodying a brake shoe, a block connected to said brake shoe and having a bifurcated end and inturned lugs on said bifurcated end, a roller mounted in the bifurcated end of said block, a

movable part having va cam surface against' which said roller contacts and having cam grooves engaged by saidinturned lugs, and means fonshifting-said movable part.

' 6. A friction brake, embodying a brake shoe, a second brake shoe, a movable base to which said second brake shoe is pivoted in such manner as to wedge against the braking surface when apphed, a member having a common braking surface for said brake shoes, separate oscillatory cam rings for positively moving said brake shoes both toward and from the braking. position,con ccntrically mounted sleeves Carr ing said cam rings, and .levers for separate y operating said sleeves. y u

7. In a friction brake, a shaft, a member having a curved braking surface in fixed relation to said shaft, a brake shoe having its contact surface formed on the arc of a circle of greater diameter than that of one struck from the pivotal point of said brake shoe but on an arc of lesser diameter than that of the'braking surface, a block movable radially with respect to said shaft to which said brake shoe is pivoted, and a cam rotatably mounted on said-shaft and exerting its force radially upon said block for positively moving 'said block and brakeA shoe both toward and from said braking surface.

8. In a friction brake, a member having` a curved braking surface. a pivoted brake shoe having its contact surface formed on the arc of a circle of greater diameter than that of one struck from the pivotal -point of said brake shoe but on an arc of lesser diameter than that of the braking surface, a movlable block to which said brake shoe is pivoted, springs between said brake shoe and the fixed part of the device andbrought into operation when said brake shoe is retracted for causing saidv brake shoe, when retracted from the braking surface, to be positioned centrally onreits pivot out- -of contact with said surface', and means for positively moving said block and brake shoe toward and from the braking surface.

9. In a friction brake, a member having a curved braking surface, agpivoted brake shoe having'. its contact surface formed on the are of a circle of greater diameter than that of one struck from the pivotal point of said brake shoe but on an are of lesser diameter than that of the braking surface, a movablefblock to which said brake shoe is pivoted, springs between said brake shoe and the fixed part of the device and coperating abutments on said brake shoe and the fixed part of the device for causing said brake shoe, when retracted from the braking surface, to be positioned centrally on its pivot out of contact with said surface, and means lfor positively moving said block and brake shoe toward and from the lbraking surface.

In testimony whereof, I have hereunto set my hand in the presenceof two subscribing witnesses.

WILLIAM o. MARSH.

Vitnesses:

JfJ. REED, J. L. HURLBERT. 

